Async Link ++

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Async Link ++ protocol for MORSE

version 7.40


1. Introduction

Async Link ++ is similar to the Async Link protocol, the difference
being the use of the complete MORSE address in the parameter.

The Async Link ++ is the simplest protocol that creates an
asynchronous link between two points. The target address is determined by
the protocol parameter. Data is transferred to the radio channel without
being modified and no CRC is used.

2. Data Format

Data is created by a arbitrary combination of bytes of length 1 to
1550 bytes, (the optimum length of the packet for transmission through the
radio network is 100 to 500 bytes).

3. Implementation in Morse

Below is an example of processing data inserted to port SCC2, which
is set with the Async Link ++ protocol:

Monitoring: source 690F5501|5.
10:34:37.035 rxsim   2 | S02
CNI mon     |toa      frm     |dst      src     |           size|TT N
10:34:37.049|                 |690F5502 690F5501|S02I   OUT    2| 89 0user
RF mon      |toa      frm     |dst      src     |lNo!DQ!RSS size|TT N
10:34:37.063|690F5502 690F5501|690F5502 690F5501|005  RFTX     2*89 4dat
  • first monitoring contains inserted data BBBB

  • second monitoring contains unchanged data after transfer through
    the protocol. A destination address is added according to the

  • the third record represents a packet sent via the radio channel
    already furnished with all addresses

The Async Link ++ protocol can identify the received character BREAK
and responses by sending 2 bytes of prot data 0x0010 (type 0A or 8A)
to the node. After receiving this data the receiving modem sends the BREAK
lenght 4 bytes it ithe serial port.

4. Configuration Parameters

The protocol uses a single parameter, which defines the address of
the opposite station.

ASYNC LINK ++ parameters:
link destination (32 bit possible)

The parameter contains the whole address and therefore it is not
necessary to set address transfer in the SIe menu. The “SIe 0uAn” option
can be chosen for using the address without any change.